1、Designation: B664 90 (Reapproved 2012)B664 18Standard Specification for80 % Silver-20 % Graphite Sliding Contact Material1This standard is issued under the fixed designation B664; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification defines the criteria for composition and other requirements for brushes with a nominal sil
3、ver content of80 %, by weight, with the balance being substantially graphite.1.2 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of the safety concerns, if any, associat
4、ed with its use. It is the responsibilityof the user of this standard to become familiar will all hazards including those identified in the appropriate Material Safety DataSheet (MSDS)(SDS) for this product/material as provided by the manufacturer, to establish appropriate safety safety, health, and
5、healthenvironmental practices, and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of Internationa
6、l Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2B613 Guide for Preparing Specifications for Miniature Brushes of Composite Materials for Sliding Electric ContactsE18 Test Methods for
7、Rockwell Hardness of Metallic Materials2.2 ANSINEMA Standard:C64.1CB-1 Brushes for Electrical Machines33. Requirements3.1 Chemical Composition, shall be as follows:Silver 80 3 % (weight)Graphite balanceTotal metal impurities 1 % maxPercent ash in graphite (ANSI C64.1) 5 % maxPercent ash in graphite
8、(NEMA CB-1) 5 % max3.2 Physical PropertiesThe following lot average properties must be met. Unless otherwise agreed between the producer andthe user, the number of samples shall be five.3.2.1 DensityThe minimum acceptable density shall be 5.15 g/cm3 as determined by the measurement and weight method
9、defined by ANSI C64.1.NEMA CB-1.3.2.2 Shear Strength:3.2.2.1 The shear strength for the normal and transverse directions shall be measured for rectangular parallelepipeds and shallbe 2000 psi (14 MPa), minimum.3.2.2.2 The shear strength for the longitudinal shear direction shall be measured for cyli
10、nders and shall be 1000 psi (6.9 MPa),minimum.1 This specification is under the jurisdiction of ASTM Committee B02 on Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee B02.05 onPrecious Metals and Electrical Contact Materials.Current edition approved May 1, 2012Nov. 1, 20
11、18. Published May 2012January 2019. Originally approved in 1979. Last previous edition approved in 20062012 asB664 81 (2006).B664 90 (2012). DOI: 10.1520/B0664-90R12.10.1520/B0664-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.o
12、rg. For Annual Book of ASTM Standardsvolume information, refer to the standardsstandards Document Summary page on the ASTM website.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.National Electrical ManufacturersAssocia
13、tion (NEMA), 1300 N. 17th St., Suite 1752, Rosslyn, VA 22209, http:/www.nema.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequ
14、ately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohock
15、en, PA 19428-2959. United States13.3 MicrostructureParts shall be visually free of structural defects, cracks, etc., upon examination at 50. The press direction,as evidenced by laminations, shall be as defined by the purchase order. Also the brush material shall not contain abrasive particlesthat wi
16、ll sliver a metal alloy ring with a hardness 110 HK100 when the brush force is equal to 30 g or that necessary for 5.0 psi(34 kPa) pressure, whichever is greater. A sliver is defined as a loose wear particle with one dimension 50 the next smallerdimension. Although slivering can be caused by coarse
17、abrasive particles, other parameters can contribute to slivering (forexample, very high brush force).3.4 Source or grade of raw materials (for example, graphite) or methods of manufacture shall not be changed without notifyingusers.4. Reference Properties4.1 Because of their size, the following prop
18、erties for miniature brushes cannot always be determined; however, these propertiesare typical for larger parts.4.1.1 Superficial HardnessThe typical Rockwell superficial hardness for this material is 44 R15W as determined by TestMethod E18 with a 18-in. steel ball.4.1.2 Specific ResistanceThe typic
19、al specific resistance for the material is 4 106 -in. (1 107 -m) as determined bythe method detailed in ANSI C64.1.NEMA CB-1.5. Certification5.1 Material supplied under this specification shall be certified as meeting the requirements of this specification by the producerof the material.6. Keywords6
20、.1 electrical contacts; graphite; silver; sliding contactsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such pate
21、nt rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn.Your comments are invited eithe
22、r for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair he
23、aring you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standar
24、d may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 182
